Various states, localities, and government agencies have adopted laws and regulations which require the use of twin wall tanks for storing fuels, chemicals, materials, gases, or the like. Such twin wall tanks must include air gaps or spaces between the inner and outer walls of the tank. These air gaps are provided with sensors which detect the flow or seepage of materials through either the outer or the inner wall of the tank. The detection of seepage signals the presence of a structural failure in either the inner or outer wall. Upon detection, the contents of the tank may be immediately removed and the tank replaced thus minimizing the possibility of contaminating the environment in the proximity of the tank with the contents thereof.
The prior art provides various twin wall tanks. Such prior art tanks are generally produced from either fiberglass or steel. Unfortunately, such prior art tanks present various disadvantages and drawbacks. Specifically, twin wall steel tanks are expensive to fabricate and are quite heavy. Steel tanks are also susceptible to the ravages of corrosion if appropriate corrosion prevention systems are not employed. Prior art twin wall fiberglass tanks are also quite expensive to fabricate. Such fiberglass tanks require a considerable number of man hours to produce for the inner wall must be fully cured and prepared before the outer wall may be formed. The preparation entails mechanically abrading or sanding the outer surface of the inner wall after a complete cure to ensure an adequate bond between the outer and the inner walls. These cure and preparation requirements are costly because they require additional man hours and they tie up expensive capital equipment.
The present invention provides a twin wall fiberglass tank and method of making the same which overcomes the disadvantages and drawbacks associated with prior art twin wall tanks.